Mary Petro, of Norwalk, has lived out of a suitcase for weeks and months at a time, traveling the world from one opera house and theater to another as a professional singer.

Perhaps that's what influenced her second career choice: real estate. Petro and her business partner Mary Ellen Gallagher work for KMS Partners, an exclusive partnership in the Riverside office of Coldwell Banker in Westport. Petro is a certified relocation specialist and previews specialist.

Spending so much time on the road made Petro value having a home to return to and influences her effort to find clients a comfortable place to call their own.

"I'm good at being a Realtor. I'm very sensitive to the thought of `This is where I belong, this is where I can make a life.' I love the idea of home. Traveling around the world I profoundly missed that," said Petro, a native of Chicago's north side. She came east to earn a master's degree in music at Yale University's School of Music.

Petro is good at being a singer, too. The lyric soprano has won prestigious singing competitions, tackled roles in many of opera's classics and modern productions, performed on renowned stages, including the Kennedy Center in Washington, D.C., and Carnegie Hall, and shared the stage with opera luminaries.

She recalled standing in the wings at the Metropolitan Opera House, where she has performed as a member of the chorus in numerous operas, to watch Renee Fleming as Desdemona in "Othello," to pick up pointers because Petro was about to perform the same role at another theater weeks later. Fleming wrote in Petro's libretto, "Wishing you great joy with your Desdemona."

Opera, in general, brings her great joy. "Opera is more than music. It's literature, it's history, it's language, it's drama," she said.

Petro is rehearsing for two operas that will be performed at the Met this fall -- "Turandot" in September and "Le Troyens" in December, and last weekend she took the stage as Musetta in Giacomo Puccini's opera, "La Bohème," at the historic Hempstead House on the Guggenheim Estate at the Sands Point Preserve on Long Island, N.Y.

"The setting is so magnificent and inspirational," she said.

That production was part of the North Shore Music Festival, which Petro co-founded.

Petro said her singing career started at an early age.

"I think I was singing from the cradle," she said.

Her parents were not performers, but she was influenced by her parents' friends, two of whom were opera singers and two of whom owned an Italian restaurant that featured weekly Opera Nights. She enjoyed growing up in the Midwest, but grew to appreciate Connecticut while matriculating at Yale.

"When I came here to Fairfield County, it felt perfect. It's very accessible to New York City, I'm close to the water, it's rich with culture and I feel I have something to contribute," Petro said. She is an active member of the arts community and performs community service work, as well as arias.

"She's fun and creative, and she can take work to the next level," Gallagher said. "We all bring different strengths to the partnership. Some of us are analytical. Mary is clearly creative," said Gallagher, who also serves with Petro as co-chairwomen of Habitat for Humanity of Fairfield County's Women Build.

"She can belt out a libretto and change the mood in a room. She can take anything we're talking about and put it to music, and she cracks people up," Gallagher said.

While Petro prefers staying closer to home these days, she has appreciated her worldly travels.

"That's one of the things I love about music -- the places it takes you," Petro said.

Last year she went to Japan as part of a Met tour.

"We were the first major arts organization that went there after

the earthquake."

For international audiences, Petro has sung Pamina in "The Magic Flute" for the Rome Festival Opera, Margarita in "Mephistofele" in Tel Aviv, Israel, and Mimi in "La Bohème" in France.